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G. H. COLLINS & M. A. MILLS. AGITATOR.

No. 499,712. Patented June 20, 1893.

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GEORGE H. COLLINS, OF BOSTON, MASSACHUSETTS, AND MELVIN A. MILLS, OF MANCHESTER, NEIV HAMPSHIRE.

AGITATO R.

SPECIFICATION forming part of Letters Patent No. 499,712, dated June 20, 1893.

Application filed December 12, 1892. Serial No. 454.814. (N0 model.)

To all whom it may concern.-

Be it known that we, GEORGE H. COLLINS, of Boston, in the county of Suffolk and State of Massachusetts, and MELVIN A. MILLs, of Manchester, in the county of Hillsborough and State of New Hampshire, citizens of the United States, have invented certain new and useful Improvements in Agitators; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to figures of reference marked thereon, which form a part of this specification.

This invention relates to apparatus designed for mixing or stirring liquid substances particularly such as contain finely comminuted or ground material, which is held in suspension in the tluid,such as ground paints, wood-pulp, or analogous substances.

This apparatus is especially adapted for paper-mills in operating upon wood-pulp or paper-pulp, which material is employed in the production of paper, itbeing found necessary to keep the pulp in constant agitation in order to make it of uniform consistency.

The object of our invention is to provide a light and effective device and further one which by a simple adjustment can be made to fit vats or tanks of various sizes Where it may be employed.

The primary and essential features of our invention consist in two central cone-shaped bodies placed base to base; moreover in a series of curved arms extending outwardly, as also in a group of tangential blades obliquely disposed with respect to the plane of rotation of the agitator, and adapted to form the outer periphery. Said blades may be composed of a number of pieces hung upon a common stud or short pin by which the width of said blades can be made adjustable, and thus the varying diameter of vats or tanks can be suited with substantially the same size of agitator.

The drawings represent in Figure 1 a plan; Fig. 2 a side elevation, and Fig. 3 a vertical sectional view of an agitator embodying our invention, Figs. 2 and 3 also showing in section a portion of the vat which receives the liquid to be operated upon. Fig. 4 is a modified construction. Fig. 5 is a cross section of one of the helical ribs.

In the present instance 1 represents a vat in part, adapted to contain an agitator 2 affixed upon a revoluble shaft3 suitablystepped. The primary features consist in two coneshaped bodies 4, 5 respectively upper and lower, placed base to base, the under one being preferably flatter or with less pitch. Attached to this under cone, and extending from the shaft outwardly are a series of cury ed arms 6 said arms being so positioned as to cause the liquid to be thrown outwardly. These arms are thin plates vertically positioned and are preferably of such depth in cross-section thattheirupperedgesareslightly above the common base of the cones, see Fig. 3. To aid in the movement of the liquid, a series of helical ribs 8 are aiiixed upon the surface of the upper cone. See Fig. l. Said ribs maybe curved in cross-section, as shown in Fig. 5, in which event the concave surface is positioned in the direction of the rotation. By this means the fluid which meets said ribs is not only given a rotary motion but is impelled downwardly owing to the shape of the said ribs.

To support and strengthen the arms 6 particularly in agitators of large size, an annular plate 9 is fastened upon the upper edges of said arms. Furthermore to increase the circulation, a series of tangential blades 10 are attached to the outer periphery of the plate 9 upon radial studs 12. Said blades are convex upon the outer edge in order that they may conform more nearly to the shape of the vat or receptacle in which they are placed, and these generally are circular. These blades 10 are moreover adjustably mounted and held by retaining nuts 13, and all are preferably maintained in a similar oblique position or at an angle with the plane of rotation of the agitator. As shown in Fig. 1', these blades may be composed of a group of metallic plates, which can be varied in shape or number to suit the varying diameters of tanks or vats in which the apparatus may be placed. In this way the agitator can be fitted to completely fill the vat and thus prevent any matter from accumulating near the outer edge of the vat. It will thus be seen that a single size of agitator can be adapted for vats of several sizes larger at very small expense.

The object of our invention is to have the flow of the liquid conform as much as possible with the natural circulation produced by rotary action; hence the upper cone is intended to direct the material away from the center, butin a downward direction; similarly the lower cone, since the apex of the latter is nearest the bottom of the vat any material collecting there is naturally crowded outwardly in order to free itself and so passes to the circumference being aided by the curved arms 6, while when it reaches the tangential blades the position of these latter is such that an upward rotary movement is imparted to said material. Thus the function of every element of the agitator is to impart outward movement, while rotary and upward motion is likewise produced in order to create a downward central feed with an upward circumferential discharge. In this way the best results are obtained, since the circulation is themost rapid.

In some instances with small agitators the annular plate 9 may be omitted in which event the blades are attached directly to the arms, the latter being sufficiently strong to resist any strain resulting from the work to be performed.

What we claim is- 1. In an agitator, the combination with a central shaft, and two oppositely disposed cone-shaped bodies thereupon, of a series of curved arms extending outwardly from the lower cone, and a number of tangential blades at the ends of said arms and oblique with respect to the plane of rotation of the agitator, substantially as explained.

2. In an agitator the combination with a revoluble shaft, and two oppositely disposed cone-shaped bodies affixed thereupon, of a series of tangential adjustable blades obliquely of the plane of rotation of the agitator, together with means for attaching said blades to the cones, substantially as specified.

3. In combination-with two revoluble oppositely disposed cone-shaped bodies having a common base, and a series of projecting arms, therefrom, a number of obliquely arranged tangential blades, each blade being composed of one or more plates,substantially as set forth and described.

4. An agitatorcomposed as follows, two revoluble oppositely disposed cone-shaped bodies, the upper one furnished with helical curved ribs, a series of projecting arms upon the lower cone, an annular plate attached to the outer ends of said arms, and a series of adjustable blades obliquely positioned with respect to the plane of rotation of the agitator, substantially as herein stated.

5. In an agitator'an upright conical body 4, the peripheral ribs 8, combined with an inverted conical body 5, a common axis for said cones, arms 6 projecting from the inverted cone and of a curvature to throw the liquid outwardly, an annular plate 9, which unites the ends of said arms, and oblique blades 10, all substantially as explained.

6. An agitator composed of a central body portion adapted to revolve and provided with radially disposed studs, and a series of tangential blades pivotally mounted upon said studs and oblique to the plane of rotation of the agitator, substantially as set forth.

7. In an agitator the combination with an upright conical body, the helical ribs thereupon curved in cross-section, of the pendant cone-shaped body 5, arms 6 projecting from the cones and of a curvature to impart centrifugal action to the liquid, a series of oblique blades, an annular plate 9 which interconnects said blades and arms, and a common shaft for rotation of the whole, substantially as set forth and specified.

In testimony whereof we affix our signatures in presence of two witnesses.

GEORGE H. COLLINS. MELVIN A. MILLS.

Witnesses to signature of George H. Collins:

H. E. LODGE, E. K.-BOYNTON.

Vitnesses to signature of Melvin A. Mills:

ALBERT 0. BROWN, LEON I. HARTWELL. 

